Manufacture of compound tubes



Invenfir (No Model.)

T. J. HOLMES.

MANUFACTURE OF COMPOUND TUBES.

FJQFE p 7,1883.

UNITED STATES PATENT @EEICE.

THOMAS J. HOLMES, OF BOSTON, MASSACHUSETTS.

MANUFACTURE OF COMPOUND TUB ES.

SPECIFICATION forming part of Letters Patent No. 275,826, dated April17, 1883.

Application filed May 29, 1882. (No model.)

To all whom it may concern Be it known that I, THOMAS J. HOLMES, acitizen of the United States, residing at Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in the Manufacture of Compound Tubes of Small Diameter; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

Figure l is an enlarged transverse section through a compound tube ofsmall diameter,

I said tube being composed of an inner and an outer tube. Figs. 2 and 3are skelps of sheet metal of the required widths to form respectivelythe inner and outer tubes of the diameters desired, one end of eachskelp being tapered to admit of its entrance within the perforation intliedie-plate, through which it' is to bedrawn. Fig. 4represents thedie-plate with its various-sized perforations. Fig. 5 is an enlargedtransverse section through a guide which I employ. Fig. 6 is an enlargedlongitudinal section through a compound tube as.

it is being drawn through the flux-trough and soldering-receptacle. Fig.7 is a longitudinal section through the die-plate and guide. Fig.

' S is an enlarged-transverse section through a compound tube formed bythe union of three tubes.

' My present in ven tion relates particularly to the mode of makingcompound tubes of small diameter, employed in the manufacture of va-'rious surgical and toilet instruments, such as atomizing-tubes,perfume-jets, &c.; and this invention consists in the several successivestages of manipulation or method of construction, and in certainmechanical devices employ ed therein, to be hereinafter fully describedand specifically claimed.

I first take a strip, a, usually termed a skelp, of sheet-brass or otherSuitable metal, of the required length and width for the formation ofthe inner tube, A, and cut one end of the same tapering, as seen in.Fig. 2, or press together the edges of this end to enable it to enterthe perforation a in the die-plate G of the required diameter. I thendraw this 5931591 (2 through its die by grasping its forwart end with apair of pinchers, D, attached to an endless belt orchain,E, the drawingoperation serving to close or nearly close the longitudinal edgestogether. Next I take a skelp, b,of the required width and length toform the outer tube, B, and taper or bend its forward end so as to enterit within a perforation, b, in the die-plate G, of corresponding size,previou'sly conducting the end of the slrelp 1) within a space,c, undera guide, F, of the form seen in Fig. 5, and located near to and parallelwith the die-plate 0, said guide being provided with a central circularplug of a diameter corresponding to that of the interior of the innertube, and having a thin bridge or knife-edge, d, extending verticallydown therefrom, the said space 0, below the guide. for the introductionand passage of the outer skelp, I), being in a line with that of thedirection of the draft. I new guide, Fig. 7, the front end of the innertube down upon the outer skelp, b, the position of the seam e of theinn-er tube, A, being directly under the point where the seam of theouter tube is to be formed, the end of the inner tube and the end of theouter skelp projecting through the die-plate sufficiently to enable themto be simultaneously grasped and pressed together by a pair of pliersattached to and drawn forward by an endless chain, E, or other suitabledevice, by which operation the seam of the outer tube, B, is closed ornearly closed. Next I cutoff the forward end of the compound tube andcleanse the longitudinal edges of the seam of the outer tube by drawingit through a soldering-flux-located in a trough, G, to adapt them forthe reception of the solder, Fig. 6. Afterward I enter the compound tubeWithin two circular openings, h, in the opposite ends of a receptacle,H, containing melted solder, located in line with the axis of the guideF and die 0, and so pivoted as to be capable of being tipped or vibratedto one side, the openings being located at such height as to be abovethe melted solder when the vessel is tipped to one side, in order thatthe tube may be entered without allowing the solder to pass within it,after which the vessel is tipped in the opposite direction to cause thesolder to flow over and lodge upon and sweat? theseam,Fig.6. Thecompound tube is finally passed through a finishing-die, which stillfurther compresses it and reduces its diameter and gives a smooth andbright appearance to its outer surface.

After forming the outer tube around the inner tube, instead ofconducting. the compound tube through the solder in the vibratingreceptacle, as described, the solder may be applied to the seam after orat the time of the application thereto of a solution of borax to cleansethe surface; or the solder may be applied in any other manner well knownin brazing; butI prefer the employment of the vibrating vesselcontaining the melted solder, owing to the facility of the operation andbecause no particle of solder can enter and obstruct the interior of theinner tube.

The solder in the receptacle H may be kept in a molten state by a seriesof gas-jets, 7c, located thereunder, Fig. 6. Where more than ordinarystrength is required I may form a third tube, I, (see Fig. 8,) outsidethe second tube, B, in a manner similar to the formation of the secondtube over the first or inner tube, the solder which seals the seam ofthe second or middle tube being made to sweat upon and around theinterior of the seam of the outer tube.

For some purposesfor instance,'to fill up the space between two objectsand serveas sleeves or bearings-the soldering or sweating of the seam ofthe outer tube may be dispensed with, the drawing of the skelp of theouter tube through its die closing the edges sufficiently for suchpurposes.

The smaller the tube to be drawn the nearer the guide F should be placedto the die-plate O; or the guide mayeven be located against the latterto prevent any possibility of the twisting of the inner tube before theouter tube is formed around it. The thickness of the die-plate should besuch as to afford a suffieient bearing-surface to insure the properclosing of the outer skelp, 1), around the inner tube.

I claim- 1. The within-described method of forming compound tubes,consisting in first making the inner tube by drawing its skelp through adie, next guiding the inner tube, and guiding and drawing through adiethe skelp to form the outer tube, with the inner tube located thereon,the seam of the inner tube being situated to one side of the seam of theouter tube, then soldering the outer seam, and finally smoothing andpolishing the outer surface of the compound tube by drawing it through afinishing-die, as set forth.

2. The guide F, in combination with the dieplate 0 and a mechanism fordrawing the tubes, substantially as described.

As one of-t-he elements 0t' an organized mechanism formanufaeturingcompound tubes, :1. soldering-receptacle, H, with thecircular openings h h at opposite ends thereof in line with the guide Fand die-plate (J, and so pivoted as to be capable of being tipped orvibrated to one side to allow the molten solder to be laid upon the seamof the outer tube, B, in combination with a means of melting the solder,as and for the purpose set forth.

Witness my hand this 24th day of May, 1882.

THUS. J. HOLMES.

In presence of- J. 0.130WKER,

G150. W. MAY.

